## Members

Members whose primary funding is from the CTCP are marked with an asterisk.

## Faculty

Mark Wise (Director)John A. McCone Professor of High Energy PhysicsEmail: wisetheory.caltech.edu Office: 412 Lauritsen I am a theoretical physicist with interests in cosmology, particle physics and nuclear physics. I have worked aspects of inflation including the production of gravitational waves, candidates for dark matter (in particular the axion) and aspects of the gravitational evolution of density perturbations. In particle physics I have contributed to our understanding of the physics of heavy quarks and proposed extensions of the standard model relevant for physics at the weak interaction scale. In the area of nuclear physics I proposed a novel effective field theory expansion relevant for the two nucleon sector that takes into account the large NN scattering S-wave scattering lengths. | |

Sean Carroll*Research ProfessorEmail: seancarrollgmail.com Office: 401 Lauritsen I'm interested in a broad spectrum of questions in theoretical physics, including cosmology, field theory, gravitation, quantum mechanics, and statistical mechanics. I've worked on models of dark energy, violations of Lorentz invariance, dark forces, black hole entropy, alternative theories of gravity, CMB anisotropies, topological defects, cosmological magnetic fields, 2D quantum gravity, dynamics of extra dimensions, inflationary cosmology, causality violation, approaches to the multiverse, foundations of quantum mechanics, the evolution of complexity, and the arrow of time.
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Clifford CheungAssistant Professor of PhysicsEmail: clifford.cheungcaltech.edu Office: 432 Lauritsen I am a theoretical physicist interested in particle physics and cosmology, with research interests in inflation, baryogenesis, and especially dark matter. My central focus is on the structure of these theories and their consequences for experiments like dark matter direct detection, cosmic ray physics, CMB, and particle colliders. I have explored a spectrum of dark matter topics, including supersymmetric models, dark sectors, non-thermal mechanisms, and asymmetric dark matter. | |

Philip HopkinsAssistant Professor of Physics Email: phopkinscaltech.edu Office: Cahill I'm interested in a range of topics that link small and large scales in the Universe. In particular, my research has focused on how galaxies form, and how stars and black holes form within those galaxies -- and then, in turn, how "feedback" from those black holes and stars (in the form of jets, radiation, winds, explosions, and more) impacts back on galaxies and successive generations of star and black hole formation. Understanding the rapidly growing body of observations within these fields, and their links to closely related fields like the formation of planets (on relatively small scales) or evolution of large-scale structure (on large ones) is a major challenge for theoretical astrophysics. | |

Hirosi OoguriFred Kavli Professor of Theoretical Physics and MathematicsEmail: ooguritheory.caltech.edu Office: 444 Lauritsen I am a theoretical physicist working on quantum field theory and quantum gravity. He is developing theoretical tools to apply superstring theory to fundamental questions in high energy physics, astrophysics, and cosmology. My research strategy is to discover hidden mathematical structures in quantum field theory and superstring theory and to exploit them to invent new theoretical tools to investigate these theories. In particular, I have developed the topological string theory to compute Feynman diagrams in superstring theory and used it to solve mysterious quantum mechanical properties of black holes. I have also worked on conformal field theories in two dimensions, D-branes in Calabi-Yau manifolds, the AdS/CFT correspondence, and properties of supersymmetric gauge theories and their relations to superstring theory. |

## Postdoctoral Researchers

Haipeng AnJohn A. McCone Postdoc in Particle Physics Email: anhpcaltech.edu Office: 419 Lauritsen I am interested in all aspects of theoretical physics. In the past, I have mainly been working on particle physics and nuclear physics. In the particle physics, I have built models to understand the properties of the dark matter, and constructed collider observables to detect simplified models with dark matter candidates. I have also worked on searching for photon-like particles in the dark sector (dark photon) with the observed properties of the stars and the dark matter detectors on the earth. In nuclear physics, I have worked on calculating the electric dipole moment of the neutron induced by general CP violating four-quark operators. | |

Francis-Yan Cyr-RacineW.M. Keck Institute for Space Studies Postdoctoral FellowEmail: francis-yan.cyr-racinejpl.nasa.gov Office: JPL 169-236A As a data-driven theoretical cosmologist, my research focuses on unravelling the mystery of the dark sector of the Universe. What particles does it contain? What are their properties? Are there new fundamental interactions? To address these questions, I study the distribution of dark-matter substructures within galactic halos through gravitational lensing. I also use observations of the cosmic microwave background and of the distribution of matter on large cosmological scales to study new physics that could govern the dark sector. On a broader level, I am interested in understanding the origins of the Universe and the fundamental laws that determine its evolution. | |

Roland De PutterCaltech Postdoctoral Scholar at JPLEmail: rdputtercaltech.edu Office: 320 Cahill/169-238 JPL I work on a variety of topics in theoretical and observational cosmology. My main goal is to learn about fundamental physics using cosmological data, such as the cosmic microwave background, weak gravitational lensing and galaxy clustering. My interests include dark energy, cosmological constraints on neutrino mass and on the number of neutrino species, and dark matter. One of my main current interests is the question of how to optimally combine information from weak gravitational lensing and galaxy clustering in order to learn about dark energy, modified gravity and other physics. | |

Christopher C. Hayward Moore Prize Postdoctoral Scholar in Theoretical AstrophysicsEmail: cchaywardcaltech.edu Office: 326 Cahill My research focuses on understanding how galaxies form using a variety of tools, including (magneto)hydrodynamical simulations, radiative transfer calculations, and (semi-)analytical models. In particular, I emphasize directly confronting simulations with observations by generating mock observations of the simulations. I have applied this technique to a wide range of astrophysical objects, such as submillimeter galaxies, active galactic nuclei, post-starburst galaxies, among others. I am especially interested in how galaxies convert their gas content into stars and what processes regulate star formation on galaxy scales. | |

Ji-hoon KimEinstein Postdoctoral Fellow in Theoretical AstrophysicsEmail: mejihoonkim.org Office: 343 Cahill My research has focused on developing a numerical framework that self-consistently depicts the interplay between galactic ingredients -- gas, stars, and massive black holes (MBHs) -- with minimal fine-tuning. I have applied this tool to various cosmological contexts including dwarf galaxies, and massive star-forming galaxies hosting MBHs. I also have helped an inter-institutional effort to compare different cosmological simulations, called the AGORA Project designed to advance galaxy formation theory across numerical platforms. As a researcher at Moore Center for Theoretical Cosmology and Physics, I aim to use my tools and experience to study how galaxies and MBHs acquire their masses in the high-redshift universe. | |

Alvise RaccanelliCaltech Postdoctoral Scholar at JPLEmail: alvisecaltech.edu Office: 346 Cahill My research is mainly focused on the large scale structure of the universe, and how it can be used to better understand the fundamental laws of nature. In particular I use observations of the clustering of structures across cosmic time to test cosmological models and theories of gravity on very large scales. My main current interests include redshift-space distortions, BAO and the ISW effect. I am part of the Prime Focus Spectrograph (PFS). I also am a member of the LOFAR and ASKAP Radio Surveys, and I am interested in studying how we can use forthcoming radio surveys for cosmology, in particular for possibly detecting modified gravity and primordial non-Gaussianity. | |

David Sanford*Moore Prize Postdoctoral Scholar in Theoretical PhysicsEmail: dsanfordcaltech.edu Office: 405 Lauritsen I am interested in phenomenology of physics beyond the standard model of particle physics, with a focus on supersymmetry and dark matter. I am interested in the constraints current and near future dark matter experiments can place on new physics models, and on the intersection of collider and dark matter results in such models. | |

Andrew WetzelMoore Prize Postdoctoral Scholar in Theoretical Astrophysics
Email: awetzelcaltech.eduOffice: 320 Cahill My research lies at the intersection of galaxy evolution and cosmic structure formation, incorporating theory, cosmological hydrodynamic simulations, and observations, including all of these in concert to inform each other. The physics of gas flows connects galaxies to cosmology, and understanding the complex interplay between cosmic inflows and feedback-driven outflows is one of the most exciting frontiers in astrophysics. I am exploring the roles of gas flows, stellar feedback, and cosmic reionization in governing the evolution of galaxies and their halos, especially for low-mass (dwarf) galaxies. I am also elucidating the physics of the cosmic environment in driving galaxy evolution in groups and clusters, particular for dwarf galaxies in the Local Group and applications to near-field cosmology. | |

Yue ZhangPostdoctoral ScholarEmail: yuezhangcaltech.edu Office: 403 Lauritsen My research focuses on theoretical particle physics and cosmology. I am interested in theories for dark matter and baryon asymmetry in the universe that make experimentally testable predictions. I am also very interested in new physics models for Higgs physics and electroweak symmetry breaking, CP violation, origin of neutrino masses, and the corresponding phenomenological aspects. |

## Students

Charles CaoGraduate StudentEmail: ccao2caltech.edu Office: 422 Lauritsen I am interested in the intersection of higher-energy physics, cosmology, and foundations of quantum mechanics, which includes topics such as quantum to classical transition, emergent spacetime, dark energy, and inflationary cosmology. I am currently exploring the possibility of space-time geometry emerging from complex many-body quantum states, particularly in the context of AdS/CFT, using tensor networks and quantum information theory. Past work involves non-perturbative aspects of quantum field theory and the Casimir effect. | |

Aidan Chatwin-DaviesGraduate StudentEmail: achatwincaltech.edu Office: 409 Lauritsen I work on problems where gravity, quantum information, and cosmology intersect. I am particularly interested in the quantum nature of spacetime and what we can learn about fundamental physics from cosmology. I am currently working on holographic tensor network models. In the past I have worked on Planck scale effects in inflation, spectral geometry, and the theory of self-adjoint extensions of symmetric operators. | |

Jason PollackGraduate StudentEmail: jpollacktheory.caltech.edu Office: 457 Lauritsen I am interested in the intersection of cosmology, the study of the universe on the largest scales, with particle physics and field theory, the study of the universe on the smallest. My current work involves application of techniques from effective field theory to compute cosmological observables. Past work has involved the cyclic/ekpyrotic model of cosmology and the effects of non-standard models of dark matter on structure formation. | |

Grant RemmenGraduate Student, Hertz Graduate Fellow/NSF Graduate Research FellowEmail: gremmentheory.caltech.edu Office: 453 Lauritsen My fields of study are theoretical high energy physics, theoretical astrophysics, cosmology, and general relativity. My spectrum of interests includes fundamental outstanding problems involving dark matter and dark energy, quantum gravity, black holes, and more. Current work includes quantum field theory around extremal black holes and inflationary cosmology. Previous work has included general relativistic three-body dynamics, HST spectroscopy of Eta Carinae, and galactic dark matter. |